But how's this for an idea to make traffic patterns greener (and, proponents say, safer): stop using traffic lights altogether. The so-called "naked streets" movement has gained traction across Europe, even in major cities like London.

The idea of streets without lights comes from a psychological principle known as risk homeostasis. It was pioneered by Gerald Wilde, a professor of psychology at Ontario's Queens University. As Jalopnik summarized, risk homeostasis suggests that:

When the level of risk in a part of the individual's life changes, there will be a corresponding rise or fall in risk elsewhere to bring the overall risk back to that individual's equilibrium. Wilde argues that the same is true of larger human systems, like a population of drivers. He argues that street signs designed to make us safer actually make us drive more carelessly by sort of nanny-ing us into complacency.

It sounds a little crazy, but it's worked in 400 towns across Europe (mostly in Germany, Holland, and Denmark). In 2007, the Dutch city of Drachten did away with street lights in 20 four-way intersections, installing traffic circles instead. The shift caused a dramatic decline in the number of traffic-related deaths: one intersection went from 36 in the four years before the shift to two the year after. And vehicles now cross the junction 20 second faster.

"The idea is to create space where there is mild anxiety among everyone so they all behave cautiously. No one thunders along at 30mph on a high street thinking that they have priority," Owen Paterson, the Dutch Transport Minister, told Jalopnik. "Instead of the State laying down the rules, we need to give responsibility back to road users."

CityFixer

Portishead, in England, ditched its lights in 2008, after residents marched up the city's main street to protest traffic and delays. The city experimented with turning the lights off, and accidents dropped. So they spent £150,000 to install mini-roundabouts and zebra crossings in place of the lights. "This ought to make crossing the road safer and quicker for pedestrians and allow motor traffic to filter and disperse, as it does through similar junctions up and down the country," Councillor David Jolley told This Is Bristol at the time